Abstract
Two bidentate NS ligands were synthesized by the condensation reaction of S-2-methylbenzyldithiocarbazate (S2MBDTC) with 2-methoxybenzaldehyde (2MB) and 3-methoxybenzaldehyde (3MB). The ligands were reacted separately with acetates of Cu(II), Ni(II) and Zn(II) yielding 1:2 (metal:ligand) complexes. The metal complexes formed were expected to have a general formula of [M(NS)2] where M = Cu2+, Ni2+, and Zn2+. These compounds were characterized by elemental analysis, molar conductivity, magnetic susceptibility and various spectroscopic techniques. The magnetic susceptibility measurements and spectral results supported the predicted coordination geometry in which the Schiff bases behaved as bidentate NS donor ligands coordinating via the azomethine nitrogen and thiolate sulfur. The molecular structures of the isomeric S2M2MBH (1) and S2M3MBH (2) were established by X-ray crystallography to have very similar l-shaped structures. The Schiff bases and their metal complexes were evaluated for their biological activities against estrogen receptor-positive (MCF-7) and estrogen receptor-negative (MDA-MB-231) breast cancer cell lines. Only the Cu(II) complexes showed marked cytotoxicity against the cancer cell lines. Both Schiff bases and other metal complexes were found to be inactive. In concordance with the cytotoxicity studies, the DNA binding studies indicated that Cu(II) complexes have a strong DNA binding affinity.
Highlights
Despite only a small difference in the backbone of their structure, Schiff bases having N and S donor atoms have been shown to possess a wide spectrum of biological activities and physicochemical properties [1,2], such as metal complexation, electrochemical, adsorptive and crystallographic properties [3,4]
Two moles of Schiff bases were reacted with 1 mol of various metal salts in an ethanol-acetonitrile solution in the ratio of 2:1 to produce the metal complexes (3–8)
The melting points were sharp indicating that the complexes were free of impurities
Summary
Despite only a small difference in the backbone of their structure, Schiff bases having N and S donor atoms have been shown to possess a wide spectrum of biological activities and physicochemical properties [1,2], such as metal complexation, electrochemical, adsorptive and crystallographic properties [3,4]. Marzano et al, (2006) reported that tris-(hydroxymethyl)phosphine copper(I) complexes containing the new bis(1,2,4-triazol-1-yl)acetate ligand showed greater in vitro antitumor activity as compared to the Schiff bases alone. These complexes were able to overcome cisplatin resistance by triggering paraptosis, a non-apoptotic mechanism of cell death in the resistant cells [16]. A new bidentate Schiff base derived from 2,4-dihydroxybenzophenone and aniline and its metal complexes were synthesized and evaluated for their DNA binding ability and the in vitro biological activity of these complexes were markedly better than that of the Schiff base. We evaluated the cytotoxicity and binding activity of these complexes for their potential as anti-cancer compounds
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
